This invention relates to a valve for regulating the flow of a fluid, in particular a variable-flow two-way valve for use in controlling actuators in an electronically controlled servo-mechanism.
It is known that, particularly in power braking and power steering hydraulic control circuits, electromagnetic valves have to be provided in order to control the flow of fluid circulating in the hydraulic circuit. It is known that proportional valves can be used for this purpose, and by means of these a fairly strict relationship can be achieved between the change in the flow of fluid in the circuit and the change in the electrical supply voltage or current to the valve. However these valves have some disadvantages, including the fact that they are rather expensive and allow fluid to pass when in the closed position.
Valves of the "on-off" type which are less expensive than the above, which are perfectly fluid-tight when the valve is closed, but with which continuous regulating of the flow is not possible, are also known.